Spring loaded earth drill



Feb. 17, 1959 v c. w. KANDLE 2,873,950

I SPRING LOADED EARTH DRILL Filed Jan. 25, 1954 v I 2 Sheets-Sheet l WW! FIG.1.- um 5 IN VEN TOR. C hqrles W. Kcmd Ze ATTORNEYS Feb. 17, 1959c. w. KANDLE SPRING LOADED EARTH DRILL 2 Sheets-Sheet ATTORNEYS.

INVENTOR. Charles W. Kanclle x jauz Filed Jan, 25. 1954 United StatesPatent SPRING LOADED EARTH-- DRILL Charles W. Kamlle, Chicago, 11].,

Application January 25, 1954,.Serial.No'. 406,030

6 Claims. (Cl.255.--4.8);

This inventionrelatesto earth drills. of relatively largediameterandparticularly to rotated bucket drills which fill whiledrillingand are periodically Withdrawn from the hole and dumped.v

Theinventionallowsv operating the drill by amotor associated therewithand provides for the downward pressure of the drill while allowing meansto. be extended to engage the sidewalls of the hole and secure the motoragainst rotation by torque reaction.

An object of the invention is'to provide for-the positive downward feedof the drill utilizing the weight of the motor associated with the drillas a unit while securing-the motor against torque reaction and verticalmovement;

The drawings "furnished.herewithyillustrate the best mode of carrying'out the invention as presently conteifiplated and set forthhereinafterr In the drawings:

Figured is a perspectiveyview of the bucket drill with the upper cutterswithdrawn and the lower end of the bucket opened for dumping thecontents of the same; Fig.2 is a vertical crosssection of part of thedrill and shows other parts including the motor and rigging in elevationwith the unit lowered in the earth and in the process of continuing thedrilling operation;

Fig. is a sectiontaken ou line 3- -3 of Fig, 2 and includes a top planview of the drillin the earth;

2 Fig.4 is an'enlarged-elevation of a part ofthe drive "shaft showingthe drive rollers accomrnodating the axial movement of the shaftrelative to the drill; and

Fig.--5 is an enlarged'section taken on line 5-5 of Fig. 2.

p The drill shown inthe drawings lIlCllldCS 'th cylinder land the lowerplate 2. Plate 2 forming the head of the drill isprovided with the leadscrew' Sand is secured at the lower end of cylinder 1 bythehinge 4 andthe latch 5. The cutters -6 fixed to plate'2 are set in the leading edgeof each of the twosector openings 7 formed in the-plate The twooppositely disposed upper cutting arms 8 extendradially-beyond the outerdimensions of cylinder 1. The inner end of the arms 8 are secured bythe' bolts 9 to the underside of the cross-head 10 welded'to extendacross the upper end of cylinder 1.

The upper rim ofcylinder 1 isrecessed as at 10a to allow the cutters toswing on bolts 9 for pivotal movement from a retracted position as shownin Figure l to an outer extended position as shown-in Fig. 2. In theextended position each cutter arm 8 abuts the crosshead and is securedinthat position by rotation of the drill in the forward direction. Arms 8may be moved initially toward extended position by centrifugal action,and thereafter their engagement with the dirt will force thenrto theextended stop position. The cutters will remain in extended positionduring drilling, and until the direction of rotation of the drill isreversed. Each cutter arm Sis provided with a sharp leading edguewhichexice tends outwardly and upwardly from the upper rimof cylinder 1 andisprovided with-the deflector plates; 11 which extend upwardly from therear side of each cutter and forwardly thereof to direct the spoil cutaway from the earth intothe upper part of the cylinder andload the same.

In operation, the rotation of the drill and the action of cutters 6 and8 loads the drill both from the bottom and the top. The spoil fromcutters 6 in advance of the cylinder 1 and. plate 2 fills the drillthrough openings 7. Cutters 8 forma 'frusto-conical face between thesmalleryhole corresponding to the diameter of cylinder 1 and the largerbore defined by cutters 8. The projecting cutters 12 adapted to engagethe abutments 13 project outwardly from the lower :edge -ofplate 2 andserve to enlarge, the opening "-forcylinder-l and reduce the resistanceof frictional contact of the cylinder with/the sidewall 'oftthesmallerbore:

Upon filling the bucket, the rotation of the drill is reversedmomentarily which causes-cutters 8 and 12 to be retracted by pivoting ina reverse direction; and the drill, is then lifted from the hole. Whenmoved away from the hole the lower plate 2 is unlatched and swingsdownwardly to open the cylinder and release the contents.

The motor 14 driving the drill is suspended by'the cable 15 and includesa shaft which fits the upper drive collarld of the drill. The removablepins 17-inserted through the drive collar 16 and motor shaft provideforthe drive "connection of the drill and motor and the supportof thecross-bar '18, fixed to collar 16. Chains 19'connecting barr18 andcross=head 10 provide for the support of the drill as in lifting themotorby the cable 15,.

The rotation of the drill is provided by thegsquare shaft 20 extendingfrom collar 16 into the square, broached bore 21 of the tube 22carriedin cross-head 10. Shaft 20 is fitted with the rollers 23v in therecesses 24- of the shaft, to project therefrom andvengage thecorresponding walls of hole 21. Rollers 23 are fitted with the sleevebearings 25 and are mounted in pairs on corresponding pins 26 whichextend across the shaft and through the recesses; Rollers 23 provide forthe axial movement of shaft 20 in tube 22 with nominal frictionalresistance while providing the transmission of torque from motor "14 tothe drillvto drive the latter.

Rotation of the shaft of motor 14 is imparted through square shaft 20and tube 22 to cylinder 1, rotation of the latter providing rotation oflead screw? and cutters 12 for drilling, togetherwith cutters 8.

The lower end of tube 22 is closed and the fiexbile sleeve 27 extendingfrorrrthe upper end of the tube to cross-bar 18 is preferably provided,as shown in Figure 2, to close the upper end of the tube and enclose thespring 28 mounted on shaft 24] between cross-head 10 and cross-bar 18.Spring 28 is of a capacity slightly less than the weight of motor 14 sothat upon lowering the motor and drill to the ground the weight of-themotor when unsupported will'compress spring 28 until the shaft is fullyretracted in tube 22.

Suitable means for handling the motor and drill as the rigging 29 andwinch 30 may be provided for raising and lowering of the motor anddrill. In starting the drilling of a hole with plate 2 fiat on theground, the motor 14 is secured against rotation by suitable bracing,not shown, and cable 15 is slacked so that the motor lowers andcompresses spring 28. Cable 15 may be here employed to maintain thedrill upright if necessary.

After drilling to a depth where the motoris level with the ground andthe bracing referred 'to cannot follow the motor into the hole, themotor, while-stillsecured by said bracing, is then supported by cable 15and the drilling continued with only the drill moving downwardly byspring 28 to a depth where the drill is supported by the chains 19.

At that depth the bracing referred to may be dispensed with and themotor lowered to again compress spring 28. The motor 14 will then be inthe ground sufficiently to allow securement of the motor against turningby the hydraulically actuated cylinders 31 secured to the motor.

Cylinders 31 extend horizontally in opposite directions and each isfitted with a piston 32 and the piston rod 33 which carries the trackshoe 34 at the outer end thereof. Shoes 34 are movable outwardly byfluid pressure supplied to cylinders 31 through the lines 35 connectedthereto, and are engageable directly with the sides of the hole or withthe vertical tracks 36 placed in the hole to engage the sides thereof.Each track 36 may be suspended from rigging 29 or from other anchorage,not shown, provided at ground level.

Retraction of shoes 34 to permit removal of the drill unit from the holefor dumping the accumulated spoil is effected by fluid pressure suppliedto cylinders 31 through lines 37 disposed on the opposite sides of therespective pistons 32 from lines 35.

The pressure system shown diagrammatically in Fig. 2 may be utilized tosupply the pressure fluid to the opposite sides of the respectivepistons 32 to alternately move shoes 34 outwardly and inwardly. Thesystem includes a supply tank 38 of hydraulic fluid and a pump 39connected thereto for developing the pressure desired. From pump 39 thefluid is moved through a pressure line 40 and through a two-positionvalve 41 which is adapted to direct the pressure fluid to either '7 lineor line 37. In the position of valve 41, as shown, the pressure fluid isbeing directed through line 35 and line 37 serves as a return line forthe hydraulic fluid. Suitable passages in valve 41 direct the returningfluid from line 37 to the return line 42 which empties into the supplytank 38. In the second position of valve 41, the pressure fluid isdirected through line 37. In this position line 35 serves as the returnline for the hydraulic fluid and communicates with return line 42through suitable passages in valve 41. V

In the operation of the drill when motor 14 is below the ground level,the engagement of shoes 34 with tracks 36 provides securement of themotor against torque reaction. Such securement generally requiresconsiderable force exerted against the walls by the cylinders 31 becauseof the size of the hole being drilled, and generally does not allowdownward sliding of the shoes on the track without elaborate Wheels orthe like which are exposed and subject to clogging and freezing.

According to the invention, vertical movement may be afforded the drillby providing relative movement of the drill and motor and with thespring 28 providing the downward pressure which would otherwise beprovided by the weight of the motor. It has been found that the limitedrelative vertical movement afforded between the motor and drill isgenerally more than adequate for the forward feed of the drill in thecourse of one filling of cylinder 1. That is, with a reasonable lengthof shaft 20 and tube 22, the limit of movement allowed by chains 19 willnot ordinarily be reached before the cylinder 1 is filled and the drilland motor unit must be raised and emptied anyway.

In addition to limiting relative movement of shaft 20 and tube 22, whichmight be provided by other abutment means, chains 19 serve with uniquesimplicity and complete reliability as a guide to the operator of therelative positions of the motor and drill. In most usual operations theshoes 34 may engage the side walls of the hole directly. The shoesshould be of a size to provide the necessary footing to securethe motoragainst torque reaction. However, in more severe conditions, the shoeswould have to be too large to be adequate.

In such cases the tracks 36, as shown, provide the foota casing wouldextend down to the shoes 34 with the lowermost section having fittingsadapted to be engaged by the shoes.

Various modes of carrying out the invention are contemplated as withinthe scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

1 claim:

1. In an earth drill unit adapted to receive and contain the spoil forperiodic removal from a hole being drilled, a cylinder, a plateremovably secured to the lower end of the cylinder and having segmentalopenings fitted with cutters for drilling in advance of the cylinder anddirecting the spoil through the openings into the cylinder, a motor unitdisposed above the cylinder, means connecting the motor and cylinder toprovide rotation of the latter, means associated with said connectingmeans to permit limited relative axial movement between said motor andcylinder in a vertical direction, extensible arms connected to the motorand adapted to engage the sides of the hole to secure the motor againstrotation by torque reaction and against vertical movement, means toextend said arms into engagement with the sides of the hole, and aspring associated with said connecting means and disposed between saidmotor and cylinder, said spring being com pressible by the weight of themotor, said drillunit being adapted to be lowered into the hole to bedrilled and said arms being adapted to be extended into engagement withthe earth after the cylinder reaches the bottom of the hole and themotor is moved downwardly to compress the spring whereby the springprovides substantially the equivalent of the weight of the motor for thedownward feed of the drill while the motor is supported vertically androtationally by said extensible arms.

2. The invention of claim 1 wherein the connecting means comprises anextensible shaft assembly including a rotatable drive shaft memberextending from the motor unit, a driven tubular member connected to thecylinder and having a bore adapted to receive the drive shaft member forrotation therewith and being movable ax ially relative thereto, androllers mounted on one of said members in rolling engagement with theother of said members to permit the free lowering of the cylinder duringthe operation of the drill.

. 3. In an earth drill unitadapted to receive and contain the spoil forperiodic removal from a hole being drilled, a cylinder, a plateremovably secured to the lower end of the cylinder and having segmentalopenings fitted with cutters for drilling a hole substantially equal tothe diameter of the cylinder and directing the spoil through theopenings into the cylinder, a motor unit disposed above the cylinder,extensible shaft means connecting the motor and cylinder and permittinglimited relative axial movement between the motor and cylinder in avertical direction, lateral arms connected to the motor and adapted toengage the sides of the hole to secure the motor against rotation bytorque reaction and against vertical movement, means to extend said armsinto engagement with the sides of the hole, a spring disposed betweensaid motor and said cylinder and providing biasing of said shaft meansto extend the same, said spring being compressible by the weight of themotor, and means secured to the axiallymovable por-' said arms adaptedto be extended into engagement with the earth upon movement of the motordownwardly and upon compression of the spring by weight of the motorwhereby the spring provides substantially the equivalent of the weightof the motor for the downward feed of the drill while the motor issupported vertically and rotationally by said arms.

4. The invention of claim 3 wherein the movement limiting meanscomprises means to provide a general visual indication of the relativepositions of the motor and cylinder.

5. In an earth drill unit adapted to receive and contain the spoil forperiodic removal from a hole being drilled, a cylinder having upper andlower open ends, a circular plate having segmental openings and beingotherwise adapted to close the lower end of said cylinder, meanssecuring said plate to the lower end of said cylinder and adapted to bereleased to allow the plate to swing downwardly and release the contentsof the cylinder, cutting teeth carried by said plate within saidopenings and adapted to remove the earth in advance of the plate uponrotation thereof with the cylinder and to deliver the spoil upwardlythrough the openings thereof into the cylinder' to fill the latter, across-member fixed to the upper end of the cylinder, opposite cuttingarms pivotally secured to said cross member and adapted to extendradially outwardly of the cylinder to enlarge the hole, each arm havingan upwardly extending frustoconical face for deflecting the spoil intothe upper open end of cylinder, a tube carried by said cross-memberconcentrically of the cylinder, a drive shaft fitting said tube andhaving a series of rollers engaging the inner walls of said tube topermit the axial movement of the shaft within the tube, a cross-armfixed to the upper end of said shaft, a spring mounted on said shaftbetween said cross-member and cross-arm, extensible connecting membersdisposed between the cross-member and crossarm to limit the relativemovement of said shaft within the tube and permit a preloading of saidspring, a drive motor having a drive shaft connected to the upper end ofsaid first-named shaft above the cross-arm to rotate the drill in eitherdirection, the bore of said tube permitting transmission of torque bysaid first-named shaft and said rollers between said motor and saidcylinder, a pair of extensible arms connected to and extending from saidmotor and adapted to engage the side wall of the enlarged hole formed bysaid radial cutting arms, means to extend said arms into engagement withthe side walls of the hole to support said motor against vertical androtational movement, the preloading of said spring being less than theweight of said motor whereby the motor when unsupported compresses thespring, the compression of said spring providing substantially theequivalent of the weight of the motor for the downward feed of the drillwhile the motor is supported vertically and rotationally by said arms,said cuttting arms being retractable upon the reverse rotation of thedrill to alllow for withdrawal of the unit from the hole and the dumpingof the contents of the cylinder.

6. In an earth drill unit adapted to receive and contain the spoil forperiodic removal from a hole being drilled, a cylinder having upper andlower open ends, a circular plate having segmental openings and beingotherwise adapted to close the lower end of said cylinder, hinge meansand a latch securing said plate to the lower end of said cylinder, saidlatch being adapted to be released to allow the plate to swingdownwardly and release the contents of the cylinder, cutting teethcarried by said plate within said openings and adapted to remove theearth in advance of the plate upon forward rotation thereof with thecylinder and to deliver the spoil upwardly through the openings thereofinto the cylinder to fill the latter, lower radial cutters pivotallysecured to the lower face of said plate and projecting beyond the radialdimentions of the cylinder for the rotation thereof with a minimum offrictional resistance, a cross-member fixed to the upper end of thecylinder, opposite cutting arms pivotally secured to said cross-memberand adapted to extend radially outwardly of the cylinder to enlarge thehole, each arm having an upwardly extending frusto-conical face fordeflecting the spoil into the upper open end of the cylinder, a tubecarried by said cross-member concentrically of the cylinder, a driveshaft fitting said tube and having a series of rollers engaging theinner walls of said tube to permit the axial movement of the shaftwithin the tube, a cross-arm fixed to the upper end of said shaft, aspring mounted on said shaft between said cross-member and cross-arm, aplurality of chains connecting said arm and the cross-member andlimiting the relative movement of said shaft within the tube to permit apreloading of said spring, a drive motor having a drive shaft connectedto the upper end of said first-named shaft above the cross-arm to rotatethe drill in either direction, the bore of said tube permittingtransmission of torque by said first-named shaft and said rollersbetween said motor and said cylinder, a pair of extensible armsconnected to and extending from said motor and having outer shoesadapted to engage the side wall of the enlarged hole formed by saidradial cutting arms, means to extend said arms to place said shoes intoengagement with the side walls of the hole to support said motor againstvertical and rotational movement, the preloading of said spring beingless than the weight of said motor when unsupported compresses thespring, the compression of said spring providing substantially theequivalent of the weight of the motor for the downward feed of the drillWhile the motor is supported vertically and rotationally 'by said arms,said radial cutters and cutting arms being retractable upon the reverserotation of the drill to allow for withdrawal of the unit from the holeand the dumping of the contents of the cylinder.

References Cited in the file of this patent UNITED STATES PATENTS463,880 Webber Nov. 24, 1901 2,091,779 Gooder Aug. 31, 1937 2,631,013Darin Mar. 10, 1953

